The paper introduces some of the recent developments in beam diagnostics,which include the beam position measurement techniques with sub-micrometer resolution,the beam size measurement techniques with sub-micrometer resolution,and the bunch length measurement techniques with sub-picosecond resolution.The cavity beam position monitor and the digital BPM signal processing technique are introduced for the beam position measurement techniques. The laser wire beam profile monitor,and the optical transition radiation/optical diffraction radiation beam size monitor are introduced for the beam size measurement techniques.The spectral techniques of coherent radiation,the transverse deflecting cavity,the rf zero-phasing technique,and the electro-optic techniques are introduced for the bunch length measurement techniques.
